The bikes may look like they've been stolen from a bunch of kids, but the blood is real enough. It was seeping through the right sleeve of Shanaze Reade's race suit as she limped away from the final of the women's BMX event, having crashed at the last corner while trying to turn silver into gold.

"I don't train as hard as I've done for a silver medal," the 19-year-old double world champion from Crewe said. "It's all about a gold or nothing. I put absolutely everything into this and the gold was there and it was still open."

She had four races today, starting with the three runs of the semi-final, over which the places in the final are decided, and she led them all out of a starting gate so precipitous that it could have been borrowed from the Hahnenkamm downhill. But she crashed in the first and last races, and eventually paid the price.

"I've cut my leg, all up there," she said when asked to describe her injuries, gingerly stroking her left calf. "I think maybe I've done something to my hand, I've done something to my sciatic nerve, and I've cut my shoulder. Quite a few things."

After the respectful hush in which so many Olympic events take place, BMX provided a bracing change of air. A mountainous ponytailed Californian called Michael Redman introduced the riders in the style of a big-fight announcer, as he does in the UCI World Super Cross series.

Big enough to stand in, if necessary, for one of the bumps that send the riders flying into the air, Redman said things like: "Awww RIGHT, Beijing, are you ready for the main event? We've got Sammy Cools, running on the five track, out of Canada... We've got Shanaze Reade, out of Great Britain..." Sitting next to him, a perspiring Chinese announcer turned the spiel into Mandarin, at considerably reduced volume.

Eight riders lined up for each race, which took place over a 350m course in which banked 180-degree bends divided straight sections featuring double and triple camel humps. Some of the jumps could be taken in more than one way, and Reade was audaciously trying to leap the triple at the end of the first straight in her first run when she caught the lip with her front wheel. Already a bike-length ahead of the field, she came down in a heap and was clipped by one of the following riders.

Crashes are so frequent in BMX - although not usually for Reade - that those who fail to complete a qualifying race benefit from a points system enabling them to continue in the competition. The British woman limped away from her first fall and proceeded to finish second in her next run, riding with understandable circumspection, before going on to win the third race, recording the fastest time of the day and earning the best starting gate for the final.

Next to her sat Anne-Caroline Chausson, a 31-year-old from Dijon who had won her first two runs and placed second in the third. Once again Reade was fast out of the gate, plunging down the slope before rearing over the opening hummocks and sliding round the first banking safely.

The French rider, however, squeezed past on the next straight and held a narrow advantage until they raced together towards the final turn.

Only the two of them were in contention for the gold medal. Knowing that she needed to gamble on repassing her opponent before the short final straight, Reade dived for the inside as they entered the turn but clipped Chausson's rear wheel and went down hard. Chausson cruised home, leading her compatriot Laetitia le Corguille and Jill Kintner of the United States into the medal positions, while Reade gathered herself up and walked half the way back before painfully remounting and freewheeling home.

"They say you learn the hard way, and I definitely learnt the hard way today," she said afterwards. "I put my heart and my soul and everything into it. But a true winner always comes back stronger and I'm going to show everyone what I'm made of."

Dave Brailsford, the performance director of British Cycling, teamed Reade with Victoria Pendleton to win the team sprint in the last two track world championships, and said he would advise her to examine the example Pendleton set by following a disaster on her Olympic debut in Athens with a gold medal four years later.

"There's a lot of pressure on her young shoulders, and in the final you probably saw experience over youth," he said. "But she's got her first Olympic Games under her belt and it looks good for London. She's got such a big engine and so much raw power that if the number of track events increases, I can certainly see her doing more than one.

"The advice I'll be giving her is to have a word with Vicky tonight and ask her how she felt. She was going to pack it in, but she came back and dominated. I think Shanaze can do the same. She's a true warrior, but you need experience, too, and today wasn't her day."